Channel estimation is commonly used in OFDM systems with coherent demodulation for channel equalization of the received signal. The transmitted OFDM signal includes predefined pilots at known sub-carrier locations, which are used for channel estimation. The transmitted pilots are sometimes scattered in the frequency domain to maintain a high utilization ratio. The receiver applies interpolation techniques to reconstruct interpolated pilots at locations where the actual scattered pilots are absent. A need continues to exist for improved estimation of Doppler spread of the channel in OFDM systems.